1. Industrial Field of Utilization
The present invention relates to a terminal device with built-in image sensor as an information appliance to be used in place of a memo pad capable of easily taking in handwritten characters or pictures or documents of printed matter, or the like, in a portable terminal device, personal computer, and the like.
2. Related art of the Invention
Recently, as the information appliances are becoming smaller in size and the information communication technology is extremely advanced, the demand for portable terminal devices is increasing abruptly.
Features of such terminal device include capability of filing of information of large capacity in small size and light weight, provision of handy input means for handwriting instead of a memo pad, and connection with communication line for transmitting and receiving data, among others.
As a result, for example, a businessman does not have to carry a large volume of documents on his business trip, and new information can be transmitted and received by connecting with the communication line from a staying place, and it provides very convenient high functions for business people.
It is hence highly expected to be a business tool in the multimedia age.
At the present, however, there are still many problems.
In particular, the conventional handwritten input means was designed to write characters or pictures directly on the touch panel provided in the front panel of the liquid crystal surface, and it was hard to use as compared with the conventional writing tool.
Besides, when taking in the printed document such as visiting card and map, a scanner or other peripheral device was separately needed.
The problems of the conventional handwritten input means are specifically described. First, to prevent the polyester film on the surface of the touch panel from being damaged, the writing tool is a special plastic pen of high sliding performance, and as compared with the conventional writing tool, it is hard to write character or picture, and when used for a long time, the surface of the touch panel is injured.
Or, when writing characters or pictures by using conventional writing tools such as pen and pencil, by writing while observing the handwriting, pictures and characters can be written as intended, but in the conventional handwritten input means, a limited handwriting is displayed depending on the resolution of the touch panel, the resolution of the liquid crystal, and the thickness of the furnished writing tool, and the writing area (touch panel) and handwriting display area (display unit) are different members, and it is hence hard to enter the characters or pictures exactly as intended.
Still more, when writing characters by conventional writing tools such as pen and pencil, individual and characteristic letters can be written depending on the size of characters or pressure on the pen, but when writing characters on the touch panel of resistance film type, a constant pressure is always required, characters and pictures appear to be similar and inexperienced if written by whoever as compared with the writing by the conventional tool. On the other hand, when taking in printed documents such as visiting card and map, a reading scanner or other device was separately needed.